Means for securing thin metal printing plates to the cylinders of printing machines



March 24, 1925. 1,531,124

MEANS FOR SECURING THIN METAL PRINTING PLATES To THE QYLINDERS J. MURRAY OF PRINTING MACHINES Filed July 1'7, 1923 6 hi firm/ways Patented Mar. 24, 1925.

UNITED STATES PATENT OFFICE.-

. .ronn Mummy, or LONDON, ENGLAND.

MEANS FOR SECURING THIN METAL PRINTING PLATES TO THE CYLINDERS OF I YRINTING MACHINES.

Application filed July 17, 1923. Serial No. 652,077.

To all whom it may concern:

Be it known that 1, JOHN MURRAY, a British subject, and a resident of London, England, have invented certain new and useful means for Securing Thin Metal Printing Plates to the Cylinders of Print- 1 ing Machines, of which the following is the specification.

The invention has for its object to provide means for the attachment of thin metal printing plates to the cylinders of printing machines, the means being such as to occupy little space on the cylinders'while giving great facility of attachment, detachment,

and adjustment, and making possible the use of thin plates for certain classes of work for which hithereto they have been unsuit-- lent element arranged with its axis parallel with the axis of the cylinder in a recess formed across the cylinder face. Means are provided for rocking this shaft through a comparatively small arc and for looking it in any position to which it is adjusted. Upon the rocking shaft are mounted detent element adapted to engage coacting or counterpart elements formed in or on the edge of the plate which is 'to be secured.

Preferably two of these devices are provided one at either end of the plate which is seized between them, adjusted circumferentially upon the cylinder by their joint adjustment and finally drawn tightly and securely into position.

It is evident that many different forms of device may be applied to the rocking shaft for its required fine rocking adjustment and final looking, but according to a simple illustrative example worm gearing is applied for this purpose.

Also it is evident that various forms of detent device may be applied to engage the plate, but according to a simple illustrative example there is adjustably carried in a series of radial apertures in the shaft, a series of fingers or posts, the outer ends of which are adapted to engage slot-like aperm rocking shaft transversely on, that is to say in the direction of the axis of the cylinder.

An illustrative example of the carrying end out of the invention is shown on an accompanying sheet of drawings, in which Figures 1 and 2 are respectively an end elevation, and a plan of part of a cylinder'in which the devices are arranged, while Figure 3 is a sectional elevation of the form of rocking shaft and finger used in the example.

' In this example the rocking shaft A is arranged in a recess cut transversely across the face of the cylinder 3. The detent elements shown separately in Figure 3 consist of fingers? B set in apertures in the shaft A and secured by set screws B They have formed upon their upper ends small beaklike projections B which engage over the edges of oval apertures C in the edges of the plates C through which the fingers enter.

Two of these gripping devices engaging the adjacent edges of two plates are shown in the drawings. Each spindle shaft A is screwed at its ends and engages within internally screwed sleeves D which sleeves are screwed externally to fit screwed apertures in carrying plates D secured to the cylinder ends. These sleeves D. serve as bearings to support the shafts A and being screwed differently as regards pitch and number of threads externally and internally serve further for the adjustment of the shafts transversely on the cylinder a fine adjustment being obtained by rotation of the sleeves by the application of a key to square apertures D in their closed outer In order to rock the shaft A for the engagement and disengagement of the plates C and to lock them when adjusted, plnions E are, provided fast on the shaft ends. With these pinions there engage pinions F fast to wormwheels G and both pivoted 011 pins H. With the wormwheels G there engage worms K formed on spindles L mounted in the plates D on which are also fast wormwheels M with which there engage screwed spindles N mounted in the. plate and provided with squared ends N for keys. There is thus provided a very fine, and owing to the fine pitch of the worms, nonreactive and looking adjustment for the shafts A, and so for the fingers B and the plates 0, which last may not only be ad? justed in position with great exactness by these means but may have very considerable tensional force applied to them so that they shall lie truly upon the cylinder. Thus, the use of very thin plates is rendered possible.

What I claim 1s:-

1. In a plate securing and adjusting device for printing machine cylinders, a rocking shaft axially parallel with the cylinder and arrangeddna transverse cavity in its periphery, and means for rocking and for locking the shaft, in combination with radial detent fingers on the shaft, said fingers having hook-like elements on their ends adapted to engage slots in the plates.

2. In a plate securing and adjusting device for printing machine cylinders, a rocking shaft axially parallel with the cylinder and arranged in a transverse cavity in its periphery in combination with means for rocklng and locking the shaft'comprising worm gearing adapted for hand adjustment.

3. In a plate securing and adjusting device for printing machine cylinders, a rocking shaft axially parallel with the cylinder and arranged in a transverse cavity in its periphery, in combination with means for rocking and locking the shaft comprising worm gearing adapted for hand adjustment, and radlal detent fingers on the shaft, said fingers havin hook-like elements on their ends adapted to engage slots in the plates.

4. In a plate securing and adjusting-devlce for printing machine cylinders, a rocklng shaft axially parallel with the cylinder and arranged in a transverse cavity in its periphery, means for rocking and locking the shaft, and radial detent fingers on the shaft, said fingers having hook-like elements on their ends adapted to engage slots in the plates, in combination with means for supporting and transversely adjusting the rocking shaft comprising externally and internally threaded sleeves, parts carried by the cylinder having apertures engaging the external threads on the sleeve, and shaft parts engaging the internal threads, said external and internal threads being of different pitches, substantially as described.

In testimony whereof I have signed my name to this specification.

JOHN MURRAY. 

